Bearing, and management system and method for the same

ABSTRACT

Installed in a ball bearing which supports a rotation axis (a supported part) freely rotatable are a control unit, a memory unit wherein specified bearing initial information proper to the ball bearing is stored, and a wireless tag equipped with a radio antenna and a transmission/reception unit which transmit/receive information between this memory unit and the exterior. Then, when the bearing motion information on the motion state of said ball bearing is input to the transmission/reception unit, the control unit has a memory unit which stores the motion information. By this, a bearing, its management system, and its management method wherein an appropriate information management is easy can be provided.

FIELD OF TECHNOLOGY

The present invention relates to a bearing such as a rolling bearingwhich supports a supported part such a rotating body, its managementsystem, and a bearing management method.

BACKGROUND TECHNOLOGY

Bearings such as rolling bearings are integrated in the core part of notonly industrial machines such as a steel rolling mill installed infactories, but a variety of apparatuses such as home electric appliancesand automobiles used by general users, and support the supported partssuch as rotating bodies inside the apparatuses.

However, in a conventional bearing such as the above, informationmanagement of the bearing has been insufficient in comparison with itsimportant role.

Specifically, in a conventional bearing in general, with respect toinitial products including trial manufactured products, manufacturingfactors such as design values and actually-measured values of sectionsare managed by the bearing manufacturer side as representative values ofthe bearing. However, with respect to mass-produced products after saidtrial manufactured product passed an acceptance inspection at thedelivering manufacturer (primary user), only marks for specifying itssize and the bearing manufacturer are applied, and even said primaryuser side managed only a small amount of information, such as themanufacturer name and item number of the bearing integrated in theproduct. Therefore, if a bearing abnormality occurred in the end user ofsaid product, inquiry to the bearing manufacturer etc. took time, andthe bearing manufacturer could not deal with the bearing abnormalityearly enough at times. In this sense, the information management in theconventional bearing was insufficient.

The present invention considers such conventional problems as the aboveand has an objective of providing a bearing, its management system, andits management method wherein an appropriate information management canbe easily performed.

DISCLOSURE OF THE INVENTION

The bearing of the present invention for achieving said objective ischaracterized by the fact that it is a bearing which supports asupported part, and a wireless tag which transmits/receives informationis attached to it.

In a bearing thus constructed, appropriate information management can beeasily performed on the corresponding bearing by utilizing said wirelesstag.

Also, it is preferred in said bearing that a memory unit be installed insaid wireless tag which stores a specified bearing initial informationproper to the bearing to which the tag is attached.

In this case, the information proper to the bearing can be instantlyobtained by reading out the bearing initial information stored in thememory unit of said wireless tag.

Also, it is preferred in said bearing that said wireless tag be attachedto a surface side other than the bearing face which makes a rollingcontact, sliding contact, or both contacts with the support face of asupported part.

In this case, said tag can be attached to the bearing in a state whereinthe wireless tag is prevented from making contact with the support face,which makes it possible to simplify the process of attaching the tag tothe bearing and to prevent the occurrence of tag breakdown caused bycontact with the support face.

Also, it is preferred in said bearing that said wireless tag is attachedto the fixed side member of the bearing.

In this case, even when the bearing moves, the wireless tag becomesimmobile at its attached position, which excludes the influence of thebearing motion to said tag as much as possible and enables easytransmission/reception of information with the tag at its immobileposition.

Also, the present invention is characterized by being a managementsystem which manages a bearing, and it is equipped with a measurementmechanism which obtains bearing motion information on the motion stateof that bearing when said bearing moves, and a writer which writes thebearing motion information from said measurement mechanism to the memoryunit of the wireless tag installed on said bearing.

In a bearing management system thus constructed, because said bearingmotion information is obtained by the measurement mechanism and isstored appropriately in the memory unit of said wireless tag by thewriter, even when an abnormal motion is performed with the bearing, theabnormal motion can be easily and accurately reproduced by reading outthe bearing motion information stored in the memory unit.

Also, the present invention is characterized by being a managementmethod to manage a bearing,

bearing motion information on the motion state of said bearing iswritten to the memory unit of a wireless tag installed on said bearingwhen the bearing moves, and the written motion information is read outto analyze the motion of said bearing.

In a bearing management method thus constructed, because said bearingmotion information is stored appropriately in the memory unit of saidwireless tag according to the bearing motion and the bearing motion isanalyzed using the stored motion information, even when abnormal bearingmotion occurs, that abnormal bearing motion can be easily and accuratelyreproduced so that an accurate and prompt investigation can be performedon the cause of occurrence of said bearing abnormality to achieve anearly resolution of the abnormality.

Also, it is preferred in said bearing management method that the writingaction of said bearing motion information in said memory unit be stoppedwhen an occurrence of abnormality is detected in said bearing.

In this case, it becomes possible to securely retain the bearing motioninformation before and after the occurrence of the bearing abnormality,thus resolution of said bearing abnormality can be performed withcertainty.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1

A figure illustrating the construction of the essential part of a ballbearing and its management system of an embodiment of the presentinvention.

FIG. 2

A block diagram showing a concrete construction example of the wirelesstag shown in FIG. 1.

FIG. 3

A cross-sectional view showing the construction of the essential part ofa multi-row angular ball bearing of another embodiment.

FIG. 4

A flow chart showing the method of integrating the ball bearing shown inFIG. 3.

PREFERRED EMBODIMENT OF THE PRESENT INVENTION

Below, preferable embodiments showing the bearing of the presentinvention, its management system, and its management method areexplained referring to the drawings. Note that the explanation below isgiven by showing the case wherein the present invention is applied to aball bearing which is integrated in rotating equipment and supports itsrotation axis to be freely rotatable.

Embodiment 1

FIG. 1 is a figure illustrating the essential part construction of aball bearing and its management system of an embodiment of the presentinvention. In the figure, installed in the management system 10 of theembodiment are a ball bearing 1, which is the subject of management, awireless tag 2 installed on the ball bearing 1 side, and a reader/writer(R/W) device 3 which can wirelessly perform bidirectional informationcommunication with the tag 2. Also, installed in this system 10 are ameasurement mechanism 4 which is connected to the R/W device 3 via awired or wireless communication path in a information-transmittable wayand measures specified actions of the ball bearing 1, and a clientterminal 5 comprising a PC (Personal Computer) connected interactivelywith the R/W device 3 via a communication network such as a LAN.Included in this client terminal 5 are not only the terminals installedin the respective manufacturers of the ball bearing 1 and the rotatingequipment but also the terminals installed in the user side who usessaid equipment, so that instructions, display, etc. of informationwritten to the wireless tag 2 or read from the tag 2 via the R/W device3 can be performed on the respective manufacturer side and user side.

Said ball bearing 1 is equipped with an inner ring 1 a as a rotatingring attached to the rotation axis S of said rotating equipment as oneunit, an outer ring 1 b as a fixed ring attached to the housing etc. ofsaid equipment, and balls 1 c arranged freely rollable between the innerand outer rings, and supports the rotating axis S to be freelyrotatable. Also, said outer ring 1 b has its outer circumference contactwith the attaching face of said housing, etc., and its axis-directionalend face fixed with a rotating equipment side member etc. in anon-contacting state.

Said wireless tag 2 is attached to the axis-direction end face of saidouter ring 1 b which is a fixed-side member, and is constructed as anRFID (Radio Frequency Identification) tag which retains and managesinformation on the ball bearing 1. Also, as the information managed bythe wireless tag 2 there are specified bearing initial informationproper to the ball bearing 1 and bearing motion information concerningthe motion state of said bearing 1 which is added appropriatelyaccording to the motion of this ball bearing 1 (the details will bedescribed later).

More concretely, also referring to FIG. 2, said wireless tag 2 isequipped with an IC chip 6 constructed using a semiconductor chip and anRF antenna 7 which has an iron core and an antenna coil rolled on it andperforms transmission/reception of radio wave, and is constructed in aone-chip wherein these chip 6 and antenna 7 are attached on a substrate.Also, the wireless tag 2 is attached to the axis-direction end face ofthe outer ring 1 b with said substrate contained in a protective casemade of metal or synthetic resin. Also, the wireless tag 2 isconstructed to be extremely light in weight and compact having itslength and width of about 0.3˜0.4 mm, and said tag 2 is attached to theball bearing 1 by fixing that case to said end face with an adhesive,etc. Furthermore, it is preferred to form an attaching section such as aconcave section on said axis-direction end face or the outercircumference face and contain the wireless tag 2 inside the attachingsection so that it will not go out of this attaching section. If thusconfigured, the tag 2 can be securely prevented from coming out of theouter ring 1 b or from developing a breakdown by contacting with aequipment-side member during the work of attaching the ball bearing 1 toa rotating equipment.

Installed in said IC chip 6 are a control unit 6 a formed including acomputing means such as a CPU, a memory unit 6 b which is constructed asnonvolatile memory and performs writing and reading of data according toinstructions from the control unit 6 a, and a transmission/receptionunit 6 c which constitutes an input/output unit which is connected tosaid RF antenna 7 and inputs/outputs information between said memoryunit 6 b and the exterior in cooperation with this antenna 7 and iscontrolled by the control unit 6 a.

Also, the IC chip 6 is equipped with a power supply unit 6 d which has acapacitor which is connected to said antenna coil and constitutes aresonating circuit together with this coil. This power supply unit 6 dis constructed so that the capacitor is charged when said RF antennareceives a radio wave of a specified (resonance) frequency and thecharged electric power is

supplied to sections of said chip 6, wherein the wireless tag 2functions as a batteryless information management tool.

Said control unit 6 a is constructed so as to perform driving control ofa modulation circuit and a demodulation circuit included in thetransmission/reception unit 6 c and manages the memory region inside thememory unit 6 b.

Specifically, when the RF antenna 7 receives a transmission wave fromsaid R/W device 3, the control unit 6 a obtains information contained inthe transmission wave from the transmission/reception unit 6 c byoperating said demodulation circuit. Included in this information is anidentification code for identifying the ball bearing 1, and the controlunit 6 a judges whether the received transmission wave was sent to saidbearing 1 or not. If the control unit 6 a has judged that it is atransmission wave to be sent to said bearing 1, the control unit 6 amakes a judgment on whether the instruction contained in thattransmission wave is a write instruction or a read instruction.

Subsequently, if the instruction received this time is a writeinstruction, the control unit 6 a has the transmission information sentwith the instruction stored in a specified region of the memory unit 6 baccording to the content of that transmission information, etc.

Also, if the instruction received at this time is a read outinstruction, the control unit 6 a reads out information specified bythat instruction from a memory region of the memory unit 6 b and has theread-out information including said identification code modulated in atransmission wave to be sent to the R/W device 3 by operating themodulation circuit of the transmission/reception unit 6 c and has ittransmitted via the RF antenna 7.

Stored in said memory unit 6 b is said bearing initial informationbefore, for example, the factory ship-out of the ball bearing 1. Thisbearing initial information is specific data on manufacturing factors ofthe ball bearing 1, and the initial information includes manufacturinghistory data such as design values and actually-measured values ofcomponents of the ball bearing 1, namely the inner and outer rings 1 aand 1 b and the balls 1 c, and initial values of assembly precisions,manufacture numbers, etc. of these elements, or basic data such as thekind and quantity of lubricating oil between the inner and outer rings 1a and 1 b.

Specifically, the bearing initial information is largely categorizedinto basic information and additional information as listed in thefollowing Table 1. Said basic information is basic and fixed informationon the ball bearing 1 to which the wireless tag 2 is attached, andincluded in this basic information are component information dividedinto the components of said ball bearing 1 for example and wholeinformation on the whole of the ball bearing 1. Also, the additionalinformation is information which is added appropriately by requests fromthe user side or service, etc. by the bearing manufacturer side, andincluded in this additional information are guidance information andremarks information for example.

TABLE 1 Bearing initial information Basic information Additionalinformation Component information Guidance information Whole informationRemarks information

Specifically, the component information comprises the basic data on thecomponents of the ball bearing 1, being data on such as design values,actually-measured values, manufacture numbers, and materials of saidinner and outer rings 1 a and 1 b and balls 1 c. Also, included in thecomponent information are, in addition to data showing the kind andquantity of said lubricating oil such as grease, data on a sealingmember which seals a ring-shape opening between the inner and outerrings 1 a and 1 b and a retainer which retains multiple balls 1 c withan equal interval in the same way as said data on balls 1 c, etc.

Also, the whole information comprises basic data on the completedproduct of the ball bearing 1, and included in this whole informationare dimension data such as bearing width and spaces at the time ofmanufacturing. Also, data showing the use conditions of the ball bearing1 such as allowable temperature and allowable load are also stored inthe memory unit 6 b as the whole information.

Because the memory unit 6 b retains the bearing initial informationincluding such component information and whole information as the above,not only the bearing manufacturer but also the primary user whointegrated the ball bearing 1 in a product and the final user whopurchased said product can immediately know the information proper tosaid ball bearing 1. Furthermore, even information which is difficult tojudge from the external appearance of the ball bearing 1, for examplethe information showing the composition of the material of said sealingmember, can be easily obtained. Also, among different kinds of greaseused according to the use temperature of the ball bearing 1, anappropriate grease can be easily selected for its use temperature.

Said guidance information is data such as guidance concerning the ballbearing 1 and said rotating equipment in which this is integrated, andincluded in this information are data on the assembly standard of saidball bearing 1 used in the manufacturing line of the user side forexample. Namely, a procedure necessary for the work of assembling theball bearing 1 into rotating equipment, appropriate assembly data valuessuch as tightening torque, press-fitting load, thrust or radial preloadof the ball bearing 1, and data showing the assembly positions relatedto the design drawing of the rotating equipment are stored in the memoryunit 6 b as the guidance information. Also, included in this guidanceinformation are data showing troubleshooting methods in case abnormaloperations occur in the ball bearing 1 and rotating equipment.

Said remarks information is data such as special remarks and precautionson the ball bearing 1 and said rotating equipment, the informationincluding data on mill sheet (steel inspection certificate) of the innerand outer rings 1 a and 1 b and balls 1 c that the bearing manufacturerobtained from the steel maker. Also, if said sealing member isconstructed of synthetic resin, usage contents such as the quantity(usage ratio) of recycled part in that sealing member, namely thesynthetic resin re-used (re-synthesized) and the resin name are storedas the remarks information. Also, depending on the performance andmaterial of the ball bearing 1, stored as the remarks information aredata showing that this ball bearing 1 is an export restricted item suchas materials subject to the security trade control or data showing thatit contains environmentally hazardous substances. Also, if data showingcontact information such as the bearing manufacturer and user (primaryuser) are retained in the memory unit 6 b as the remarks information,when trouble has occurred with the ball bearing 1 or rotating equipment,it can be immediately reported to the manufacturer.

Also, said bearing motion information which is stored appropriately inthe memory unit 6 b is data which varies according to the actual motionstate of the ball bearing 1, and this motion information includes motiondata measured by the measurement mechanism 4 such as temperature,vibration value, or noise value around the ball bearing 1, or the numberof rotation of the rotation axis S (ball bearing 1) with which thebearing motion can be analyzed. Note that this motion data are updatedsuccessively according to the storage capacity of the memory unit 6 b,and the memory unit 6 b is designed to hold at least the most recentmotion data. Specifically, in the memory unit 6 b a memory region of aspecified data size is assigned to the motion data of the bearing motioninformation, and the memory unit 6 b is constructed so that it updatessaid motion data from the data of the oldest storing date. Also, thismemory unit 6 b is constructed to stop bearing motion information update(write) operation according to the instruction from the control unit 6a, wherein, when the client terminal 5 detects an abnormality in theball bearing 1 based on the measurement data of the measurementmechanism 4, bearing motion information write operation is stopped bysending a stop writing instruction from this terminal 5 to the controlunit 6 a. Because bearing motion information write operation in thememory unit 6 b is stopped when an abnormality is thus detected in theball bearing 1, it becomes possible to retain the bearing motioninformation before and after the occurrence of the bearing abnormalitysecurely in the memory unit 6 b.

Returning to FIG. 1, said R/W device 3 contains an antenna whichperforms wireless communication with the RF antenna 7 of the wirelesstag 2, wherein the R/W device 3 exchanges data with the wireless tag 2responding to the direct operation by the operator or the remoteoperation using the client terminal 5 to said device 3. Also, installedin this R/W device 3 is a display which can display said identificationcode, write data, read data, etc. so that the operator can immediatelygrasp data read from the wireless tag 2 and visually perceive datawritten from the measurement mechanism 4 to the tag 2. Furthermore,preferably used as the R/W device 3 is a handy-type one constructedfreely portable by the operator, to read and write bearing initialinformation or bearing motion information for multiple ball bearings 1.

Said measurement mechanism 4 is equipped with a detection means foracquiring said bearing motion information, specifically measurementinstruments such as a temperature meter, a vibrometer, a noise meter, ora tachometer. These measurement instruments detect each correspondingmotion data at each specified sampling cycle and output them to the R/Wdevice 3. Also, as said measurement instruments those installedindependently from said rotating equipment and those installed asdefault in said equipment for controlling the rotating equipment can beused. Also, as the measurement instruments, not only those whichdirectly measure data such as temperature but also an ammeter whichmeasures the supplied electric current value to an electric motor whichdrives the rotation axis S can be used for example, and those whichindirectly measure data on the number of rotation based on the detectedvalue of this ammeter can be also used.

In this embodiment constructed in the above way, when the ball bearing 1operates, the measurement mechanism 4 acquires said bearing motioninformation, and the R/W device 3 has the bearing motion informationfrom the measurement mechanism 4 stored in the memory unit 6 b of thewireless tag 2. Also, because said bearing initial information is storedin the memory unit 6 b, even when an abnormality occurs to the ballbearing 1 due to long-term changes or an inappropriate operation, byreading the bearing initial information and bearing motion informationstored in the memory unit 6 b, that abnormal action can be easily andprecisely analyzed and reproduced to perform a verification test. Asthis result, it becomes possible to resolve the cause of said bearingabnormality precisely and early, and an early resolution of the bearingabnormality can be achieved. Also, because the most recent bearingmotion information is stored in the memory unit 6 b, it becomes possibleby using these most recent motion data to warn the operator before anabnormality occurs to the ball bearing 1 and to also prevent bearingabnormality. Also, because information is read from or written to thememory unit 6 b of the tag 2 through wireless communication between thewireless tag 2 and the R/W device 3, information management of the ballbearing 1 integrated inside rotating equipment can be securely performedwithout disassembling said equipment.

Also, in this embodiment, because the wireless tag 2 is attached to theaxis-direction end face of the outer ring 1 b, said tag 2 is attached toa face other than the track face (bearing face) where said balls 1 croll, and the tag 2 is attached to the ball bearing 1 in a state wherecontact with the outer face (support face) of the rotation axis (asupported part) S is prevented to simplify attaching a tag to the ballbearing 1. Furthermore, because contact between the wireless tag 2 andsaid support face is prevented, occurrence of tag breakdown due to itscontact can be prevented.

Also, because the wireless tag 2 is attached to the outer ring 1 b whichis a fixed member of the ball bearing 1, this tag 2 ends up fixed to theattached position inside the rotating equipment, thus influences ofbearing rotation motion on said tag 2 is excluded as much as possible,and even when using a small-output R/W device 3 having a narrowtransmission/reception range of radio wave, wireless communicationbetween this device 3 and the tag 2 can be easily performed.

Furthermore, because the wireless tag 2 is attached to the ball bearing1 itself, even when the ball bearing 1 is detached from the rotatingequipment and used in another machine, the wireless tag 2 can be movedtogether with the ball bearing 1. Hence, the bearing initial informationand bearing motion information stored in said memory unit 6 b can bemoved together with said ball bearing 1, always utilizing its bearinginitial information and the accumulated bearing motion informationeffectively. Also, because the bearing information can be moved togetherwith the ball bearing 1 in this way, different from the case whereinbearing information is recorded and managed by recording it on a form(e.g., an inspection score sheet), misplacement and loss of the bearinginformation can be prevented, and further there is no need to separatelysecure a place to store bearing information.

Embodiment 2

FIG. 3 is a cross-sectional view showing the essential part constructionof multi-row angular ball bearing of another embodiment. In the figure,the main difference between this embodiment and said embodiment is thatthe application is to a multi-row angular ball bearing used inautomobile wheel hubs.

In FIG. 3, the multi-row angular ball bearing 11 of this embodiment isequipped with a pair of inner rings 11 a 1 and 11 a 2 which are dividedin two along the axis, and a single outer ring 11 b whose whole isformed as one unit. Also, installed in this ball bearing 11 are multipleballs 11 c 1 arranged freely rollable between the inner ring 11 a 1 andthe outer ring 11 b, and multiple balls 11 c 2 arranged freely rollablebetween the inner rign 11 a 2 and the outer ring 11 b. These balls 11 c1 and 11 c 2 roll on the corresponding track surfaces of the inner andouter rings in a state wherein they are retained at a specified intervalby retainers 11 d 1 and 11 d 2. Also, installed in a ring-shape openingbetween said inner ring 11 a 1 and outer ring 11 b is a sealing member11 e 1 made of synthetic resin. Similarly, installed in a ring-shapeopening between the inner ring 11 a 2 and outer ring 11 b is a sealingmember 11 e 2 made of synthetic resin, preventing rainwater, foreignmaterials, etc. from invading the bearing interior together with saidsealing member 11 e 1.

Said inner rings 11 a 1 and 11 a 2 are assembled as one unit with theaxle (a supported part) 30 of said automobile tires so that theyfunction as rotating rings. Specifically, in one inner ring 1lal, saidinner ring 1lal is attached to the axle 30 in a state wherein itsaxis-direction end face is in contact with a flange section of one endside of the axle 30. Also, in the other inner ring 11 a 2, said innerring 11 a 2 is attached to the axle 30 in a state wherein itsaxis-direction end face is in contact with a nut 31 screwed to the screwsection of the other end side of the axle 30. By adjusting thetightening force to this nut 31, a specified (thrust) preload is appliedto the ball bearing 11 (the details will be described later).

Said outer ring 11 b functions as a fixed ring, fixed as one unit to theautomobile-side housing (to be more detailed, a tube section of saidwheel) 32. Also, this outer ring 11 b has a cut-out section 11 b 1formed on a part of its outer circumference. Installed on this cut-outsection 11 b 1 is a load sensor, such as a distortion gauge 20 forexample, for measuring said preload applied to the ball bearing 11. Alsoattached to the cut-out section 11 b 1 is a metallic cover 12, designedto protect the distortion gauge 20.

Also, installed on the axis-direction end face of the outer ring 1lb issaid wireless tag 2, constructed so that bi-directional communicationwith the R/W device 3 can be performed. Note that it may be such aconstruction that instead of said cut-out section 11 b 1, a surroundinggroove is formed all around the outer circumference of the outer ring 11b, the distortion gauge 20 is installed in said surrounding groove, andfurther the wireless tag 2 is installed.

Also, connected to the wireless tag 2 distortion gauge 20 via a signalline which is omitted in the figure, wherein the detection results ofthis gauge 12 are transmitted to the R/W device 3 (FIG. 1).Specifically, installed in said transmission/reception unit 6 c (FIG. 2)is an interface unit to which the detected signal from the distortiongauge 20 can be inputted, and said detected signal in the analog formatis converted into a digital signal in the digital format in thisinterface unit. Then, the control unit 6 a (FIG. 2) stores said datasignal showing the detected preload value as bearing motion informationin the memory unit 6 b (FIG. 2) and has the transmission/reception unit6 c forward it to the client terminal 5 (FIG. 1) via the R/W device 3.

Also, information such as gauge property proper to the distortion gauge20 necessary for integrating the ball bearing 11 (namely, said assemblystandard) is pre-stored in said memory unit 6 b as the guidanceinformation of said additional information. Specifically, the distortiongauge 20 has delicately different output characteristics (gaugeproperties) depending on the actually attached position to said cut-outsection 11 b 1, the attaching accuracy such as attaching strength, orthe sensor characteristic of the gauge itself. In order to monitordetection signals of multiple distortion gauges 12 with the samemonitor, gain adjustment of the amplifying circuit which amplifies itssignal output needs to be performed. Because the gauge property of thedistortion gauge 20 attached to the ball bearing 11 thus varies from onebearing to another, the bearing manufacturer side grasps the optimalgauge property on the automobile manufacturer side monitor before thefactory shipment and stores that grasped gauge property in the memoryunit 6 b as additional information in advance.

Specific actions in this embodiment are explained hereafter, withreference to FIG. 4. Note that in the following explanation the assemblyprocess for integrating the ball bearing 11 into the automobile side ismainly explained.

As shown in FIG. 3, once the inner rings 1lal and 11 a 2 and the outerring 1lb of the ball bearing 11 are tentatively assembled to the axle 30and the housing 32, respectively, as shown in Step S1 in FIG. 4, aworker has the R/W device 3 read out guidance information including thegauge property of the distortion gauge 20 stored in the memory unit 6 band has it transferred to the client terminal 5. Installed in thisclient terminal 5 is said amplifying circuit functionally with softwarefor example, and in this terminal 5 a gain value included in thetransferred gauge property is extracted. Then, in the amplifying circuitof this client terminal 5, optimal gain adjustment is performed for thedistortion gauge 20 installed on the ball bearing 11 (Step S2 ).

Afterwards, in the client terminal 5, detected signals of the distortiongauge 20 sent out via the wireless tag 2 and the R/W device 3 are inputand amplified in said amplifying circuit, and then displayed on thedisplay (Step S3). Then, the worker adjusts the tightening force to saidnut 31 so that the specified preload is applied to the ball bearing 11while checking the display to integrate said ball bearing 11.

As in the above, in this embodiment, because the memory unit 6 b storesas the additional information the gauge property etc. of the distortiongauge 20 attached to the ball bearing 11, it becomes possible tointegrate the ball bearing 11 easily and precisely to the specifiedpreload without performing amplifier adjustment in the automobilemanufacturer side.

Whereas in the explanations in said Embodiment 1 and Embodiment 2 casesof applying to a ball bearing which supports freely rotatable therotation axis S of rotating equipment and a multiple-row angular ballbearing integrated in an automobile wheel hub are explained, the presentinvention may be anything wherein a wireless tag which can send andreceive information is installed on a bearing which supports a supportedpart, and its bearing form and supported part are not limited at all tothose in the above. Specifically, it can be applied to various kinds ofbearings such as rolling bearings such as roller bearing, conic rollerbearing, and needle roller bearing, sliding bearings, and linear motionbearings which support a linearly moving supported part with a rollingor sliding contact. Also, it can be applied to a dynamic load bearingwherein a dynamic load generating groove is formed on one side.

Also, whereas in the above explanation a management system use of an R/Wdevice was explained, the management system of the present invention maybe anything which can write said bearing motion informationappropriately to the memory unit according to the bearing motion,wherein the R/W device may be replaced with a writer device.

Also, whereas explained in the explanation of said Embodiment 1 was aconstruction wherein validation test is performed using the bearinginitial information and bearing motion information stored in the memoryunit when an abnormality occurs, the present invention is not limited tothis. For example, it may have a construction wherein conditions (suchas usage temperature and time) necessary for judging the degradation ofsaid grease are included in the bearing initial information andpre-stored in the memory unit, and the control unit utilizes theseconditions and data such as temperature detected by a temperature sensorinstalled outside the bearing or directly on the bearing to judge thedegree of degradation of said grease. Namely, by utilizing the controlunit and the memory unit of the wireless tag, a bearing having aself-diagnosis function can also be constructed and managed.

Also, whereas explained in the explanation of said Embodiment 1 wasconstruction wherein the bearing motion information write operation inthe memory unit is stopped when the client terminal has detected anabnormality in the ball bearing based on the measurement data of themeasurement mechanism, the present invention is not limited to this, butthe control unit of the wireless tag may be given an abnormalitydetection function based on said measurement data and the bearing motioninformation write operation may be stopped according to the abnormalitydetection result in this control unit.

Also, whereas construction was in the explanation of said Embodiment 2in which the wireless tag and the distortion gauge are connected, thewireless tag converts the detected analog signal into digital data andsend it to the client terminal side, the present invention is notlimited to this but may have a construction wherein a separatetransmitter is installed to analog-transmit the detected signal from thedistortion gauge.

1. A bearing system comprising: a bearing which supports a supportedpart; a wireless tag which transmits/receives information is attached tothe bearing, the wireless tag including a memory unit, and bearingmotion information on a motion state of said beating being writable tothe memory unit when the bearing moves, wherein the memory unit storesspecified bearing initial information proper to the bearing; ameasurement mechanism which obtains the bearing motion information onthe motion state of the bearing when the bearing moves; and a writerwhich writes the bearing motion information from the measurementmechanism to the memory unit.
 2. The bearing described in claim 1,wherein said wireless tag is attached to a surface side other than thebearing face which makes a contact including a rolling contact, slidingcontact, or both to the support face of the supported part.
 3. Thebearing described in claim 1, wherein said wireless tag is attached to afixed-side member of the bearing.
 4. A bearing management systemcharacterized by being a management system to manage a bearing, it isequipped with a measurement mechanism which obtains bearing motioninformation on the motion state of the bearing when said bearing moves,and a writer which writes the bearing motion information from saidmeasurement mechanism to a memory unit of the wireless tag installed onsaid bearing, wherein the memory unit stores specified bearing initialinformation proper to the bearing.
 5. A bearing management methodcharacterized by being a management method to manage a bearing, by whichbearing motion information on the motion state of said bearing iswritten to a memory unit of a wireless tag installed on said bearingwhen the bearing moves, and the written motion information is read outto analyze the motion of said bearing, wherein the memory unit storesspecified bearing initial information proper to the bearing.
 6. Abearing management method characterized by being a management method tomanage a bearing, by which bearing motion information on the motionstate of said bearing is written to a memory unit of a wireless taginstalled on said bearing when the bearing moves, and the written motioninformation is read out to analyze the motion of said bearing, whereinwhen an abnormality is detected in said bearing, write operation of saidbearing motion information in said memory unit is stopped.
 7. Thebearing described in claim 1, wherein said wireless tag is attached to asurface side other than the bearing face which makes a contact includinga rolling contact, sliding contact, or both to the support face of thesupported part.
 8. The bearing described in claim 1, wherein saidwireless tag is attached to a fixed-side member of the bearing.
 9. Thebearing described in claim 2, wherein said wireless tag is attached to afixed-side member of the bearing.
 10. A bearing system comprising: abearing which supports a supported part; a wireless tan whichtransmits/receives information is attached to the bearing, the wirelesstan including a memory unit, and bearing motion information on a motionstate of said bearing being writable to the memory unit when the bearingmoves; a measurement mechanism which obtains the bearing motioninformation on the motion state of the bearing when the bearing moves;and a writer which writes the bearing motion information from themeasurement mechanism to the memory unit, wherein when an abnormality isdetected in said bearing, the memory unit stops storing the bearingmotion information on the motion state of the bearing.
 11. The bearingsystem described in claim 1, further comprising a reader to read out thebearing motion information stored in the memory unit so as to analyzethe motion of the bearing.
 12. A bearing system comprising: a bearingwhich supports a supported part; a wireless tag which transmits/receivesinformation is attached to the bearing, the wireless tag including amemory unit, and bearing motion information on a motion state of saidbearing being writable to the memory unit when the bearing moves,wherein the memory unit stores specified bearing initial informationproper to the bearing; a reader which reads out the bearing motioninformation stored in the memory unit so as to analyze the motion of thebearing.
 13. A bearing system comprising: a bearing which supports asupported part; a wireless tag which transmits/receives information isattached to the bearing, the wireless tag including a memory unit, andbearing motion information on a motion state of said bearing beingwritable to the memory unit when the bearing moves; a reader which readsout the bearing motion information stored in the memory unit so as toanalyze the motion of the bearing, wherein when an abnormality isdetected in said bearing, the memory unit stops storing the bearingmotion information on the motion state of the bearing.
 14. The bearingmanagement system of claim 4, further comprising a reader which readsout the bearing motion information stored in the memory unit so as toanalyze the motion of the bearing.
 15. A bearing management systemcharacterized by being a management system to manage a bearing, it isequipped with a measurement mechanism which obtains bearing motioninformation on the motion state of the bearing when said bearing moves,and a writer which writes the bearing motion information from saidmeasurement mechanism to the memory unit of the wireless tag installedon said bearing, wherein when an abnormality is detected in saidbearing, the memory unit stops storing the bearing motion information onthe motion state of the bearing.
 16. A bearing for a wheel hub in anautomobile, comprising: an outer ring having a cut-out section formed onan outer circumference for fitting on a housing of the automobile; aninner ring for fitting on an axle; a plurality of balls arranged betweenthe outer ring and the inner ring; a distortion gauge mounted to thecut-out section of the outer ring, for measuring a preload applied tothe bearing; and a wireless tag installed on the bearing having a memoryunit storing output characteristics of the distortion gauge by receivingdetection results of the distortion gauge and storing specified bearinginitial information proper to the bearing.
 17. A bearing managementsystem using the bearing of claim 16, comprising a client terminalhaving an amplifying circuit wherein gain adjustment is performed byreceiving the output characteristics stored in the wireless tag.
 18. Thebearing system of claim 1, wherein guidance information for assembly ina manufacturing line is stored in the memory unit.
 19. The bearingsystem of claim 1, wherein remarks information includes special remarksand precautions on the bearing and a rotating equipment is stored in thememory unit.
 20. The bearing system of claim 19, wherein the remarksinformation relates to recycled parts.
 21. The bearing system of claim19, wherein the remarks information relates to export restricted items.22. The bearing system of claim 19, wherein the remarks informationrelates to environmentally hazardous substances.